Analysis of a Single-Ended GaN-Based Drain-Pumped Mixer for Radar Applications

The aim of the present paper consists of a deep analysis concerning the impact of the GaN HEMT technology. Two methods of analysis were implemented. The first one is based on the time-varying power series approach which is based on simple measure of the I/V characteristics, thus allowing for experimental-based predictions without the need of manufacturing the mixer. The device I/V characteristics and the relative derivatives were extracted in a dynamic way as to avoid the dispersion phenomena to which the GaN technology is affected. The second method is based on the harmonic-balance analysis of a designed GaN HEMT DP mixer operating in S-band, whose relative simulations were performed by means of a commercial CAD. The analyzes was repeated for different local-oscillator power levels (PLO ) as to capture the CL and IIP3 behaviors when the PLO> 10 dBm. Both the analysis methods show improvements at high PLO. In particular, the IIP3 reveals a peak for PLO≈ 21 dBm caused by a sweet spot of the output third-order intermodulation products (IMP3) occurring at the same PLO.